There are recording medium driving devices for reproducing information signals recorded on the disc-shaped recording mediums. In certain ones of the recording medium driving devices, a slider held by a holder is moved in one direction when a recording medium is held on the holder to lower the holder to load the recording medium on the loading unit, while the slider is moved in the opposite direction to elevate the holder to eject the recording medium from the holder by an ejection lever.
As typical of this sort of the recording medium driving device, there is known a device shown in FIGS. 1 to 5. With this driving device, upwardly opened guide grooves 102, 102 are formed in both lateral sides of a chassis 101. In these guide grooves 102, 102, there are slidably supported a pair of rearwardly positioned support pins 104, 104 provided on both lateral surfaces of a holder 123, there being another pair of forwardly positioned similar support pins provided on both lateral surfaces of the holder 123.
On the holder 123, there is mounted a slider 105 for sliding in the fore-and-aft direction. The slider 105 includes lateral surface sections 106, 106 and a connecting portion 107 interconnecting the lateral surface sections 106, 106. In the lateral surface sections 106, 106, there are cam grooves 108, 108 which are spaced apart from each other in the in the fore-and-aft direction. In the cam grooves 108, 108, the support pins 104, 104 of the holder 123 are supported for sliding movement. A slider biasing spring 109 is mounted under tension between the lateral surfaces 106, 106 of the slider 104 and a rearward portion of the chassis 101 for biasing the slider 105 rearwards.
At the rear end of the chassis 101, there is mounted a lever supporting lug 110, and an ejection lever 111 is rotatably mounted at the foremost part of the supporting lug 110. A lever biasing spring 112 is mounted under tension between the ejection lever 111 and the holder 123 for biasing the ejection lever 111 in a direction indicated by arrow R1 in FIG. 1. The foremost part of the ejection lever 111 is provided with an operating piece 113 which is bent downwards.
Before insertion of the recording medium into the holder 123, the ejection lever 111 includes a control edge 114 engaged with a mating control edge 116 of the slider 105 so that the slider 105 is held at its foremost movement stroke end (see FIGS. 1 and 2).
When a recording medium 117 is inserted from the forward side into the holder 123, the operating piece 113 of the ejection lever 111 is thrust rearwards by the recording medium 117, so that the ejection lever 111 is rotated in the direction indicated by arrow R2 against the bias of the lever biasing spring 112 (see FIG. 3). When the ejection lever 111 is rotated in the direction indicated by arrow R2 in FIG. 3, the control edge 114 is disengaged from the mating control edge 116, so that the slider 105 is slid rearwards by the slider biasing spring 109 (see FIG. 4).
When the slider 105 is moved rearwards, the positions of the support pins 104, 104 of the holder 123 in the cam grooves 108, 108 are changed, such that the rearward side support pins 104, 104 are moved within the guide grooves 102 of the chassis 101 to cause descent of the holder 123 (see FIG. 5). With the descent of the holder 123, the recording medium 117 which it holds is loaded on a loading unit, not shown, thereby setting up a state enabling the reproducing operation of information signals for the recording medium 117. The slider 105 is moved rearwards at this time as the mating control edge 116 has a sliding contact with a portion of the ejection lever 111. The ejection lever 111 has its portion engaged with the mating control edge 116 of the slider 105, moved rearwards, so that the ejection lever is held at the end of the rotation indicated by arrow R2.
When the reproducing operation comes to a close, such that an ejection button, not shown, is actuated, a driving motor, not shown, is rotated to cause forward movement of the slider 105 under the driving force of the motor against the biasing force of the slider biasing spring 109.
When the slider 105 is moved forwards, the positions of the support pins 104, 104 of the holder 123 in the cam grooves 108, 108 are changed, such that the holder 123 is lifted by the rearward side support pins 104, 104 being moved in the guide groove 102b of the chassis 101.
When the slider 105 has been moved forwards by the ejection lever 111, the ejection lever 111 is rotated by the lever biasing spring 112 in a direction indicated by arrow R1. Consequently, the recording medium 117 is thrust forwards and ejected out of the holder 123 by the operating piece 113 of the ejection lever 111.
When the slider 105 is moved to a forward side preset position, the rotation of the driving motor ceases. The slider 105 is moved rearwards, under the force of the slider biasing spring 109, and the mating control edge 116 is engaged with the control edge 114 of the ejection lever 111, which is positioned at the end of the movement stroke in the direction R1. The slider 105 again is held at the forward end in the range of movement.
In the above-described recording medium driving device of the related art, described above, the lever biasing spring 112 for biasing the ejection lever 111 and the slider biasing spring 109 for biasing the slider 105 are required, with the consequence that the number of components is correspondingly increased. When inserting the recording medium 117 into the holder 123, the slider 105, moved towards rear, has a sliding contact with the ejection lever 111. Since the lever biasing spring 112 at this time is in the fully stretched state, the frictional resistance between the slider 105 and the ejection lever 111 is large, with the result that the slider 105 and the ejection lever 111 are lowered in durability. Moreover, the load imposed on the driving motor for ejecting the recording medium 117 is increased in an amount corresponding to the increased frictional resistance between the slider 105 and the ejection lever 111, thus increasing the power consumption.
Another instance of the recording medium driving device is a recording and/or reproducing apparatus for recording and/or reproducing information signals for the recording medium. In a certain type of this recording and/or reproducing apparatus, there is such an apparatus in which, when the recording medium is held by the holder, the slider held by the holder is moved in one direction to lower the holder to load the recording medium on the loading unit, and in which, when the slider is moved in the opposite direction, the holder is elevated, at the same time as the recording medium is ejected by the ejection lever from the holder.
As this sort of the recording and/or reproducing apparatus, there is such apparatus constructed as shown in FIGS. 6 and 7.
The recording and/or reproducing apparatus, shown in FIGS. 6 and 7, includes a holder 201 movable vertically relative to the chassis.
The holder 201 is movable vertically relative to the chassis, not shown. A cam lever 202 is supported by the holder 201 for sliding in the fore-and-aft direction. The cam lever 202 includes a cam 203 and a vertically extending support leg 204, which support leg 204 is supported for movement in the up-and-down direction in a support opening 205 formed in the chassis.
A supporting piece 206 is provided on the upper surface of the holder 201. The supporting piece 206 rotationally supports a head shift lever 207. The head shift lever 207 is provided with a mating operating portion 208 that is in sliding contact with the cam 203 of the cam lever 202.
A pickup includes a mounting portion 209. On the upper surface of the mounting portion 209, there is mounted a rear end of a head mounting plate 211, the distal end of which carries a magnetic head 210. The head mounting plate 211 is formed of an elastic material.
The above-described holder 201 and the chassis etc are arranged within an outer casing of the recording and/or reproducing apparatus. A top plate 213 of the outer casing is provided on top of the holder 201.
FIG. 6 shows the state in which the magnetic head 210 is at a first retreat position. During reproduction of information signals from a recording medium, for example, the magnetic head 210 is not in use, so that the magnetic head 210 is retreated from the recording medium held on the holder 201, and is at the first retreat position. At this time, the mating operating portion 208 of the head shift lever 207 is engaged with the uppermost end of the cam 203 of the cam lever 202, with the head mounting plate 211 being lifted by the head shift lever 207 in a forwardly descending state. The magnetic head 210 is at a position of being retreated from the recording medium held by the holder 201 right above the upper surface of the holder 201.
When the information signal reproducing operation for the recording medium has been finished, such that the recording medium is ejected forwards from the holder 201, the holder 201 is moved upwards from the state of FIG. 58, while the cam lever 102 is also moved upwards in unison with the holder 201 (see FIG. 7).
When the holder 201 and the cam lever 202 are moved upwards, the relative position between the head shift lever 207 and the cam 203 is not changed. However, since the cam 203 is at substantially the same height level as the mounting portion 209, the magnetic head 210 is moved to a second retreat position with a rising gradient in the forward direction, so that the magnetic head 210 is at a higher height level than the above-mentioned first retreat position (see FIG. 7).
In the above-described recording and/or reproducing apparatus of the related art, the head mounting plate 211, which has been lifted with the forwardly descending gradient, is lifted with a forwardly rising gradient when the recording medium is ejected from the holder 201. As a consequence, in the recording and/or reproducing apparatus of the related art, there is required a large space between the upper surface of the holder 201 and the outer casing 213 of the outer casing, in order to permit the magnetic head 210 to be moved between the first and second retreat positions, thus increasing the overall thickness of the recording and/or reproducing apparatus.
Moreover, the recording medium driving device is designed for recording and/or reproducing information signals for the disc-shaped recording medium loaded on the disc table. This sort of the disc recording and/or reproducing apparatus includes an ejection mechanism for ejecting the disc-shaped recording medium loaded on the disc table on completion of the recording and/or reproduction of the information signals, and a head movement mechanism for causing movement of the magnetic head, adapted for applying the magnetic field to the disc-shaped recording medium during recording, in a direction into contact with or away from the disc-shaped recording medium.
In certain versions of this sort of the recording medium driving device, both the operations of the ejection mechanism and the head movement mechanism are operated by the driving power of a sole driving motor, in order to make common use of the sole driving motor. In a disc recording and/or reproducing apparatus of the related art, in which a sole driving motor is used in common, a slider is supported for movement on a holder holding a disc-shaped recording medium, and is moved a first movement amount in one direction with respect to the holder. On completion of the loading, the slider is moved by a second movement amount relative to the holder in the same sole direction by the driving motor to actuate the head movement mechanism, and the magnetic head is moved in a direction of contacting with the so loaded disc-shaped recording medium to set up the recording mode.
Consequently, when the recording of the information signals has come to a close, the driving motor is rotated in reverse, while the slider is moved relative to the holder in a direction opposite to the aforementioned one direction by a second amount of movement, with the magnetic head being moved in a direction away from the disc-shaped recording medium to cancel the setting of the recording mode. When the disc-shaped recording medium is to be ejected in the canceled state of the setting of the recording mode, rotation of the driving motor is continued to cause the slider to be moved relative to the holder by the first amount of movement in an opposite direction to the aforementioned one direction to cause the operation of the ejection mechanism.
In the above-described driving device of the related art, when the recording of the information signals has come to a close and the disc-shaped recording medium is to be ejected, the slider is moved in the same direction to actuate the ejection mechanism or the head movement mechanism, so that a movement stroke corresponding to the sum of the first and second amounts of movement is required.
As a consequence, the recording medium driving device is increased in size by an amount corresponding to the increased amount of the slider movement stroke.
There is also a recording medium driving device adapted for driving a disc cartridge in a casing member of which a disc-shaped recording medium is rotatably mounted and in which a shutter is also supported for sliding on the casing member.
In such driving device, the shutter is slid by a shutter opening/closing mechanism, usually at the time of inserting the disc cartridge into the holder to open a through-hole formed in the casing member to permit the laser light to be illuminated from a light source of the optical pickup to the disc-shaped recording medium contained in the casing member.
The shutter slid is held at an open position, however, if the shutter is vibrated in this case to produce resonant vibrations, it may be impossible to maintain optimum reproducing operations for the disc-shaped recording medium of the disc driving device.
In order to combat this inconvenience, a certain disc driving device of the related art includes retention means, such as a spring plate, on a portion of an outer casing, in the inside of which a holder or a chassis is mounted, such that, when the disc-shaped recording medium is loaded on the disc table, the shutter is retained by this retention means to suppress the vibrations which will otherwise be produced.
In the recording medium driving device of the related art, in which the retention means are provided at a portion of the outer casing thereof, the vibrations transmitted from outside to the disc driving device tends to be transmitted to the shutter through the retention means, with the result that vibrations cannot be suppressed sufficiently.